diff --git a/src/openrct2/network/network.cpp b/src/openrct2/network/network.cpp
index 94ec42b6f6..29578cd9ec 100644
--- a/src/openrct2/network/network.cpp
+++ b/src/openrct2/network/network.cpp
@@ -151,6 +151,15 @@ void Network::Close()
 		// which may no longer be valid on Linux and would cause a segfault.
 		return;
 	}
+
+	// HACK Because Close() is closed all over the place, it sometimes gets called inside an Update
+	//      call. This then causes disposed data to be accessed. Therefore, save closing until the
+	//      end of the update loop.
+	if (_closeLock) {
+		_requireClose = true;
+		return;
+	}
+
 	if (mode == NETWORK_MODE_CLIENT) {
 		delete server_connection->Socket;
 		server_connection->Socket = nullptr;
@@ -178,6 +187,8 @@ void Network::Close()
 
 	CloseChatLog();
 	gfx_invalidate_screen();
+
+	_requireClose = false;
 }
 
 bool Network::BeginClient(const char* host, uint16 port)
@@ -362,6 +373,8 @@ uint8 Network::GetPlayerID()
 
 void Network::Update()
 {
+	_closeLock = true;
+
 	switch (GetMode()) {
 	case NETWORK_MODE_SERVER:
 		UpdateServer();
@@ -370,6 +383,12 @@ void Network::Update()
 		UpdateClient();
 		break;
 	}
+
+	// If the Close() was called during the update, close it for real
+	_closeLock = false;
+	if (_requireClose) {
+		Close();
+	}
 }
 
 void Network::UpdateServer()
@@ -405,6 +424,8 @@ void Network::UpdateServer()
 
 void Network::UpdateClient()
 {
+	assert(server_connection != nullptr);
+
 	switch(status){
 	case NETWORK_STATUS_CONNECTING:
 	{
diff --git a/src/openrct2/network/network.h b/src/openrct2/network/network.h
index bb70bfd599..f2ea55f2cb 100644
--- a/src/openrct2/network/network.h
+++ b/src/openrct2/network/network.h
@@ -195,6 +195,8 @@ private:
 
 	sint32 mode = NETWORK_MODE_NONE;
 	sint32 status = NETWORK_STATUS_NONE;
+	bool _closeLock = false;
+	bool _requireClose = false;
 	bool wsa_initialized = false;
 	ITcpSocket * listening_socket = nullptr;
 	uint16 listening_port = 0;
diff --git a/src/openrct2/object.h b/src/openrct2/object.h
index eaa00e9617..3a563d3650 100644
--- a/src/openrct2/object.h
+++ b/src/openrct2/object.h
@@ -114,8 +114,8 @@ sint32 object_calculate_checksum(const rct_object_entry * entry, const void * da
 sint32 find_object_in_entry_group(const rct_object_entry* entry, uint8* entry_type, uint8* entry_index);
 void object_create_identifier_name(char* string_buffer, size_t size, const rct_object_entry* object);
 
-rct_object_entry *object_list_find_by_name(const char *name);
-rct_object_entry *object_list_find(rct_object_entry *entry);
+const rct_object_entry * object_list_find_by_name(const char *name);
+const rct_object_entry * object_list_find(rct_object_entry *entry);
 
 void object_entry_get_name(utf8 * buffer, size_t bufferSize, const rct_object_entry * entry);
 void object_entry_get_name_fixed(utf8 * buffer, size_t bufferSize, const rct_object_entry * entry);
diff --git a/src/openrct2/object/ObjectRepository.cpp b/src/openrct2/object/ObjectRepository.cpp
index a2361c9327..5ba2ddb533 100644
--- a/src/openrct2/object/ObjectRepository.cpp
+++ b/src/openrct2/object/ObjectRepository.cpp
@@ -717,18 +717,28 @@ bool IsObjectCustom(const ObjectRepositoryItem * object)
 
 extern "C"
 {
-    rct_object_entry * object_list_find(rct_object_entry * entry)
+    const rct_object_entry * object_list_find(rct_object_entry * entry)
     {
-        IObjectRepository * objRepo = GetObjectRepository();
-        const ObjectRepositoryItem * item = objRepo->FindObject(entry);
-        return (rct_object_entry *)&item->ObjectEntry;
+        const rct_object_entry * result = nullptr;
+        auto objRepo = GetObjectRepository();
+        auto item = objRepo->FindObject(entry);
+        if (item != nullptr)
+        {
+            result = &item->ObjectEntry;
+        }
+        return result;
     }
 
-    rct_object_entry * object_list_find_by_name(const char * name)
+    const rct_object_entry * object_list_find_by_name(const char * name)
     {
-        IObjectRepository * objRepo = GetObjectRepository();
-        const ObjectRepositoryItem * item = objRepo->FindObject(name);
-        return (rct_object_entry *)&item->ObjectEntry;
+        const rct_object_entry * result = nullptr;
+        auto objRepo = GetObjectRepository();
+        auto item = objRepo->FindObject(name);
+        if (item != nullptr)
+        {
+            result = &item->ObjectEntry;
+        }
+        return result;
     }
 
     void object_list_load()
diff --git a/src/openrct2/rct1/S4Importer.cpp b/src/openrct2/rct1/S4Importer.cpp
index 411110d2c0..8ef3bbc2ee 100644
--- a/src/openrct2/rct1/S4Importer.cpp
+++ b/src/openrct2/rct1/S4Importer.cpp
@@ -468,7 +468,7 @@ private:
             std::vector<const char *> objects = RCT1::GetSceneryObjects(sceneryTheme);
             for (const char * objectName : objects)
             {
-                rct_object_entry * foundEntry = object_list_find_by_name(objectName);
+                const rct_object_entry * foundEntry = object_list_find_by_name(objectName);
                 if (foundEntry != nullptr)
                 {
                     uint8 objectType = foundEntry->flags & 0x0F;